/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.flink.testutils;

import org.apache.flink.configuration.Configuration;
import org.apache.flink.configuration.GlobalConfiguration;

import java.io.BufferedWriter;
import java.io.File;
import java.io.FileWriter;
import java.io.IOException;

/** Utility class to help test the Flink configuration. */
public final class TestConfigUtils {

    public static Configuration loadGlobalConf(String[] keys, String[] values, File tempDir)
            throws IOException {
        return loadGlobalConf(getConfAsString(keys, values), tempDir);
    }

    public static Configuration loadGlobalConf(String contents, File tempDir) throws IOException {
        File confDir;
        do {
            confDir = new File(tempDir, TestFileUtils.randomFileName());
        } while (confDir.exists());

        try {
            confDir.mkdirs();
            final File confFile = new File(confDir, GlobalConfiguration.FLINK_CONF_FILENAME);

            try {
                BufferedWriter writer = new BufferedWriter(new FileWriter(confFile));
                try {
                    writer.write(contents);
                } finally {
                    writer.close();
                }
                return GlobalConfiguration.loadConfiguration(confDir.getAbsolutePath());
            } finally {
                confFile.delete();
            }
        } finally {
            confDir.delete();
        }
    }

    public static String getConfAsString(String[] keys, String[] values) {
        if (keys == null || values == null || keys.length != values.length) {
            throw new IllegalArgumentException();
        }

        StringBuilder bld = new StringBuilder();

        for (int i = 0; i < keys.length; i++) {
            bld.append(keys[i]);
            bld.append(": ");
            bld.append(values[i]);
            bld.append(System.lineSeparator());
        }
        return bld.toString();
    }

    // ------------------------------------------------------------------------

    private TestConfigUtils() {}
}
